; | |
Object.defineProperty(exports, "__esModule", { | |
value: true | |
}); | |
exports.default = retry; | |
var _wrapAsync = require('./internal/wrapAsync.js'); | |
var _wrapAsync2 = _interopRequireDefault(_wrapAsync); | |
var _promiseCallback = require('./internal/promiseCallback.js'); | |
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } | |
function constant(value) { | |
return function () { | |
return value; | |
}; | |
} | |
/** | |
* Attempts to get a successful response from `task` no more than `times` times | |
* before returning an error. If the task is successful, the `callback` will be | |
* passed the result of the successful task. If all attempts fail, the callback | |
* will be passed the error and result (if any) of the final attempt. | |
* | |
* @name retry | |
* @static | |
* @memberOf module:ControlFlow | |
* @method | |
* @category Control Flow | |
* @see [async.retryable]{@link module:ControlFlow.retryable} | |
* @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an | |
* object with `times` and `interval` or a number. | |
* * `times` - The number of attempts to make before giving up. The default | |
* is `5`. | |
* * `interval` - The time to wait between retries, in milliseconds. The | |
* default is `0`. The interval may also be specified as a function of the | |
* retry count (see example). | |
* * `errorFilter` - An optional synchronous function that is invoked on | |
* erroneous result. If it returns `true` the retry attempts will continue; | |
* if the function returns `false` the retry flow is aborted with the current | |
* attempt's error and result being returned to the final callback. | |
* Invoked with (err). | |
* * If `opts` is a number, the number specifies the number of times to retry, | |
* with the default interval of `0`. | |
* @param {AsyncFunction} task - An async function to retry. | |
* Invoked with (callback). | |
* @param {Function} [callback] - An optional callback which is called when the | |
* task has succeeded, or after the final failed attempt. It receives the `err` | |
* and `result` arguments of the last attempt at completing the `task`. Invoked | |
* with (err, results). | |
* @returns {Promise} a promise if no callback provided | |
* | |
* @example | |
* | |
* // The `retry` function can be used as a stand-alone control flow by passing | |
* // a callback, as shown below: | |
* | |
* // try calling apiMethod 3 times | |
* async.retry(3, apiMethod, function(err, result) { | |
* // do something with the result | |
* }); | |
* | |
* // try calling apiMethod 3 times, waiting 200 ms between each retry | |
* async.retry({times: 3, interval: 200}, apiMethod, function(err, result) { | |
* // do something with the result | |
* }); | |
* | |
* // try calling apiMethod 10 times with exponential backoff | |
* // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds) | |
* async.retry({ | |
* times: 10, | |
* interval: function(retryCount) { | |
* return 50 * Math.pow(2, retryCount); | |
* } | |
* }, apiMethod, function(err, result) { | |
* // do something with the result | |
* }); | |
* | |
* // try calling apiMethod the default 5 times no delay between each retry | |
* async.retry(apiMethod, function(err, result) { | |
* // do something with the result | |
* }); | |
* | |
* // try calling apiMethod only when error condition satisfies, all other | |
* // errors will abort the retry control flow and return to final callback | |
* async.retry({ | |
* errorFilter: function(err) { | |
* return err.message === 'Temporary error'; // only retry on a specific error | |
* } | |
* }, apiMethod, function(err, result) { | |
* // do something with the result | |
* }); | |
* | |
* // to retry individual methods that are not as reliable within other | |
* // control flow functions, use the `retryable` wrapper: | |
* async.auto({ | |
* users: api.getUsers.bind(api), | |
* payments: async.retryable(3, api.getPayments.bind(api)) | |
* }, function(err, results) { | |
* // do something with the results | |
* }); | |
* | |
*/ | |
const DEFAULT_TIMES = 5; | |
const DEFAULT_INTERVAL = 0; | |
function retry(opts, task, callback) { | |
var options = { | |
times: DEFAULT_TIMES, | |
intervalFunc: constant(DEFAULT_INTERVAL) | |
}; | |
if (arguments.length < 3 && typeof opts === 'function') { | |
callback = task || (0, _promiseCallback.promiseCallback)(); | |
task = opts; | |
} else { | |
parseTimes(options, opts); | |
callback = callback || (0, _promiseCallback.promiseCallback)(); | |
} | |
if (typeof task !== 'function') { | |
throw new Error("Invalid arguments for async.retry"); | |
} | |
var _task = (0, _wrapAsync2.default)(task); | |
var attempt = 1; | |
function retryAttempt() { | |
_task((err, ...args) => { | |
if (err === false) return; | |
if (err && attempt++ < options.times && (typeof options.errorFilter != 'function' || options.errorFilter(err))) { | |
setTimeout(retryAttempt, options.intervalFunc(attempt - 1)); | |
} else { | |
callback(err, ...args); | |
} | |
}); | |
} | |
retryAttempt(); | |
return callback[_promiseCallback.PROMISE_SYMBOL]; | |
} | |
function parseTimes(acc, t) { | |
if (typeof t === 'object') { | |
acc.times = +t.times || DEFAULT_TIMES; | |
acc.intervalFunc = typeof t.interval === 'function' ? t.interval : constant(+t.interval || DEFAULT_INTERVAL); | |
acc.errorFilter = t.errorFilter; | |
} else if (typeof t === 'number' || typeof t === 'string') { | |
acc.times = +t || DEFAULT_TIMES; | |
} else { | |
throw new Error("Invalid arguments for async.retry"); | |
} | |
} | |
module.exports = exports.default; |